1. Field of the Invention
The present invention relates to a method and a device for controlling a driver assistance system.
2. Description of Related Art
Driver assistance systems are known which support the driver in keeping to a selected traffic lane. For this purpose, the driver assistance system includes assistance functions, such as LDW (lane departure warning) and LKS (lane keeping support). Assistance function LDW warns the driver of leaving the traffic lane by generating optical and/or acoustic and/or haptic signals. Assistance function LKS actively intervenes in on-board systems of the vehicle, such as the steering system and/or the braking system or an ESP system, in order to keep a vehicle deviating from the traffic lane in the traffic lane.
For this purpose, the driver assistance system includes a sensor system including in particular at least one video sensor for recording traffic lane markings or the like.
Such Driver assistance systems are known, for example, from published German patent document DE 103 11 518.
From published German patent document DE 101 37 292, a method is known for operating a driver assistance system of a vehicle, particularly of a motor vehicle, having servo-supported steering. This method is characterized by the following steps:                recording or estimating surroundings data, preferably of an instantaneous traffic situation,        recording or estimating preferably instantaneous motion data of the vehicle,        comparing the recorded or estimated surroundings data to the motion data of the vehicle,        modifying the support of a steering handle in accordance with the comparison.        
When a specified system boundary is reached, for instance, by the loss of the traffic lane or its marking, the exceeding of a maximum value of the transverse acceleration, or the like, these assistance systems deactivate by reducing the steering torque applied to the steering wheel by the assistance system. The driver then has to take over again completely the transverse guidance of the vehicle himself. If this takes place abruptly in difficult driving situations, such as in cornering, it may not only be perceived by the driver as disturbing, but may also bring on a difficult situation.
In the following, by an LKS function we shall understand a function for the transverse guidance of the vehicle, with whose aid the vehicle is able to be kept in one's own traffic lane.